Mobile computing devices may have touch buttons (i.e., buttons) integrated in the touchscreen panel. These buttons are back-illuminated, screen-printed glyphs that perform specific operating system functions when pressed (e.g., go to home screen). Generally, it is preferable to design mobile computing devices to support different operating systems. Unfortunately, different operating systems have different button requirements.
One approach to this problem requires creating different touchscreen panels. The touchscreen panels for different operating systems would have different screen-printed buttons, and the operating system would prescribe which touchscreen panel to assemble into a touch-display assembly. Since assembling the touch-display assembly requires optically bonding the touchscreen panel to a graphical-user-interface (GUI) display (i.e., display), the assembly process is typically not reversible. As a result, supporting mobile computing devices with different operating systems would require creating, manufacturing, and stocking different touchscreen panels. This approach is costly, inefficient, and therefore undesirable.
Another approach would utilize “soft buttons” for these system functions. Soft buttons are icons rendered on the display. This approach requires dedicating display area to the buttons. As a result, the display area for other functions would be reduced. Usable display area is among the features highly valued by users, and reducing display area is generally considered undesirable. The display area loss may be mitigated, to some extent, by reducing the size of the soft buttons, but this may cause reduced usability and/or visibility of the buttons. In addition, the display is amongst the mobile computing device's most expensive parts. Using the display for buttons is cost inefficient. For these reasons, soft buttons are also undesirable.
Therefore, a need exists for integrating buttons into the touchscreen panel without using valuable GUI display area and without creating different touchscreen panels for each operating system.